New: Iraq has closed its main southern border crossing with Iran until further notice, on the orders of Prime Minister Ali al-Zaidi.

New: Iraq has closed its main southern border crossing with Iran until further notice, on the orders of Prime Minister Ali al-Zaidi.

Officials said the closure allows for a security review and the installation of equipment to stop the smuggling of prohibited substances.

Al Shib is a key route for food, construction materials and Iranian pilgrims heading to Najaf and Karbala.

Officials said other crossings with Iran are expected to be gradually closed, which could disrupt trade and raise prices in southern Iraq.

Trade between the two countries reached 10 billion dollars last year.

Tehran protested that it had not received advance notice, as required by bilateral rules.